Aviation fuel

ABSTRACT

A jet aviation fuel based on aliphatic ethers is disclosed wherein the fuel comprises a compound according to the invention, a mixture of compounds according to the invention, a mixture of the pure or mixed aliphatic ethers admixed with conventional jet aviation fuel, or a mixture of said ethers with conventional hydrocarbon fuel, thus giving a product conforming to a jet aviation fuel standard.

This application is an international application claiming priority fromDanish patent application no. PA2010 00471. All patent and non-patentreferences cited in the present application, are hereby incorporated byreference in their entirety.

FIELD OF INVENTION

The present invention relates to the field of fuels, specificallyaviation fuels for use in jet engines.

BACKGROUND OF INVENTION

Aviation fuel specifications are among the most restrictive among allfuel specifications, reflecting the combination of extreme temperaturesencountered during flight, and the consequence of failure characteristicof the aviation industry. A car engine failing may be a major nuisancewhereas the failure of a plane engine can lead to disaster. As aconsequence of these fuel specifications are stringent, rarely changedand in general based on a very cautious approach towards modification.The same viewpoint is reflected in implementation of e.g. new enginetechnologies be that jet or internal combustion engines.

Chief requirements according to jet aviation fuel specifications areconcerned with performance at low temperature, imposed to reduce therisk of fuel lines clogging due to precipitation of compounds at lowtemperature. Commercial jet aviation fuel is a complex mixture ofhydrocarbons, varying according to production locale and feedstock, allcomplying with common specifications.

Currently, offerings in bio-fuels are either bio-ethanol, which do notlive up to current engine technology as ethanol is hygroscopic, cannotform homogenous mixtures with jet aviation fuel and that lastly have anenergy density that is approximately 70% of current jet aviation fuel.Other fuel types are bio-Diesel, made by the transesterification offatty materials be that from plants or from animal sources. The longchain esters composing bio-Diesel are only partially compatible withcurrent use in jet aviation, not only due to unfavourable physicalproperties, but also due to the fact that ester hydrolysis can lead toclogging of fuel lines due to precipitation of fatty acids. Furtherdetracting from possible use in jet aviation applications are the factthat fatty acids are surface active agents, and can thus act assurfactants in situations where this in decidedly unwanted. Thus currentregulations limit the allowed content of fatty acid esters to less than5 ppm in fuel pipeline systems—used in e.g. larger airports.

The application of ethers as fuel additives is not unknown intransportation fuels. Methyl-tert-butyl ether has seen extensiveapplication as an anti-knock additive to petrol since its introductionin the seventies. Ethers have been prepared by a variety of routes, suchas condensation of alcohols in the presence of catalysts such asconcentrated sulphuric acid, ferric chloride and acid zeolites(Kirk-Othmer Encyclopedia of Chemical Technology, ISBN 9780471238966vol. 10 p 567-583). A new route for the preparation of dibutyl ether hasbeen disclosed in patent application US20100204522, utilizing an ionicliquid reaction medium. The document describes the industrial utility ofdibutyl ether: “Ethers, such as the dialkyl ethers produced by theprocesses hereof, are useful as solvents, plasticizers and as additivesin transportation fuels such as gasoline, diesel fuel and jet fuel.”

EP1218472 (U.S. Pat. No. 7,014,668) teaches the use of a complex mixtureof different organic compounds, with different oxygen containingfunctionalities for a fuel replacement for both diesel- and jet-fuel.Specifically the document discloses that one should use a mixturecontaining “A total of at least four different oxygen-containingfunctional groups are present in at least two differentoxygen-containing organic compounds.”, thus excluding systems derivedfrom less complex compounds or mixtures.

US2009013591A1 teaches the use of more complex glycol ethers, alsocontaining hydroxy functionalities, either as glycol or glycerol ethers,for improvement of vapour pressure and cetane value of the blended fuelof the invention. For use in jet-fuel the document teaches the use ofthe additives in the replacement of conventional de-icing additives,either in full or in part.

CN101423781 teaches the application of mixtures containing substitutedethers as fuel additives, specifying the use of a complex mixturecontaining terpene, 2-propanone, alkylene glycol ethers, dibasic methylester, nonyl phenol ethoxylate, and 0-15% mineral oil. The additivesserve to eliminate deposit formation.

JP10316979A teaches the use of ethers, including aromatic and benzylicethers for increasing engine power in internal combustion gasolineengines. The ethers are characterized by all being methyl ethers, andfurther in that the long chain of the ether is 5-6C alkyl, phenyl orbenzyl; the aliphatic ethers of the document being examples of knownanti-knock additives for gasoline. Further the document teachespossibility of adding further 0-30% of an aromatic compound, other thanan ether, presumably in order to further enhance the octane number ofthe gasoline fuel of the invention.

The use of alkyl-ethers, either as pure compounds or in mixtures withvariation of the chain-length of the substituted ethers allows for asimpler fuel formulation, where the ethers can be obtained directly fromalcohols of biological origin. Furthermore a formulation based onethers, or ethers in conjunction with conventional fuel components willbe simpler in relation to fuel infrastructure, as only interaction ofone type of functional group with said infrastructure (pumps, gaskets,fuellines etc.) will have to be investigated. Furthermore the ethershave the advantage of very low ability to solubilise water, thusreducing problems with water absorbtion. Lastly the ethers are fullymiscible with conventional fuel components in all proportions.

The term “comprising” in the present application is intended to conveythe idea of a collection of items that are relevant for the presentinvention, but it does not exclude that further items may be presentand/or relevant. The term “comprising” is not intended to convey theidea of a completeness to the exclusion of other items, which would bebetter described by the expression “consisting of”.

SUMMARY OF THE INVENTION

In a main aspect the present invention relates to a jet aviation fuelcomprising one or more aliphatic ether compound having the generalformula (I):

R1-O—R2

wherein R1 and R2 individually are selected from aliphatic carbonchains.

In other aspects the invention relates to containers and aerial vehiclescomprising said jet aviation fuel.

DETAILED DESCRIPTION OF THE INVENTION

The present invention discloses ethers that can be used directly in jetaviation fuel applications, or in jet aviation fuel applications whenadmixed with conventional jet aviation fuel, or in jet aviation fuelapplication when admixed with conventional hydrocarbon fuel, where theensuing product conforms to jet aviation fuel specification. By theexpression ‘conventional hydrocarbon fuel’ is intended a fuel distillatethat does not conform to jet aviation fuel standards. Ethers arehydrolytically robust, non-hygroscopic and exhibit physical chemicalproperties that are compatible with specifications for jet aviationfuel. Not only the melting point but also the boiling point of the fuelcan be controlled by choice of chain lengths or proportion of differentethers in the fuel. Furthermore the ethers can find application inmixtures with standard jet aviation fuel, or the ethers can be used tochange the physical properties of fuel, not conforming to standards inthe pure state, so that said fuel can fit within jet aviationspecifications.

In the Table 1 is shown the physical properties of selected examples ofthe compounds disclosed in the invention, in comparison with twodifferent jet-fuel specifications (conventional jet aviation fuel) andBio-Diesel.

TABLE 1 Boiling Melting Density Name, systematic Name Formula Point ° C.point ° C. g/cm3 Butane, 1-propoxy- Propyl butyl ether C₇ H₁₆ O 118.10.772 ± 0.06 Butane, 1,1′- Diisopentyl ether C₁₀ H₂₂ O 172-174 0.7777oxybis[3-methyl- Pentane, 1-propoxy- Propyl pentyl ether C₈ H₁₈ O 142.2± 3.0 0.780 ± 0.06 Pentane, 1-(1- Isopropyl pentyl C₈ H₁₈ O 129.9 ± 3.00.778 ± 0.06 methylethoxy)- ether Pentane, 1-butoxy- Butyl pentyl etherC₉ H₂₀ O 163.8 ± 8.0 0.772 Pentane, 1,1′-oxybis- Pentyl ether C₁₀ H₂₂ O184-186 −69 0.791 ± 0.06 Hexane, 1-methoxy- Methyl hexyl ether C₇ H₁₆ O125.9 ± 3.0 0.772 ± 0.06 Hexane, 1-ethoxy- Ethyl hexyl ether C₈ H₁₈ O135.5 ± 2.0 0.7700 Hexane, 1-propoxy- Propyl hexyl ether C₉ H₂₀ O 165.4± 3.0 0.786 ± 0.06 Hexane, 1-(1- Isopropyl hexyl C₉ H₂₀ O 152.3 ± 3.00.784 ± 0.06 methylethoxy)- ether Hexane, 1-butoxy- Butyl hexyl etherC₁₀ H₂₂ O 184.4 ± 8.0 0.791 ± 0.06 Hexane, 1-(1- (1-Methylpropyl) C₁₀H₂₂ O 175.7 ± 8.0 0.790 ± 0.06 methylpropoxy)- hexyl ether Hexane, 1-Pentyl hexyl ether C₁₁ H₂₄ O 204.1 ± 8.0 0.795 ± 0.06 (pentyloxy)-Hexane, 1,1′-oxybis- Hexyl ether C₁₂ H₂₆ O 221-224 0.7936 Heptane,1-methoxy- Methyl heptyl C₈ H₁₈ O 150.5 ± 3.0 0.780 ± 0.06 etherHeptane, 1-ethoxy- Ethyl heptyl ether C₉ H₂₀ O 165.5 ± 3.0 −68.3 0.786 ±0.06 Heptane, 1-propoxy- Propyl heptyl ether C₁₀ H₂₂ O 187.1 ± 3.0 0.791± 0.06 Heptane, 1-butoxy- Butyl heptyl ether C₁₁ H₂₄ O 204.1 ± 8.0 0.795± 0.06 Heptane, 1- Pentyl heptyl ether C₁₂ H₂₆ O 222.9 ± 8.0 0.799 ±0.06 (pentyloxy)- Heptane, 1-(3- Isoamyl heptyl C₁₂ H₂₆ O 214.9 ± 8.00.798 ± 0.06 methylbutoxy)- ether Octane, 1-methoxy- Methyl octyl etherC₉ H₂₀ O 173.5 ± 3.0 0.786 ± 0.06 Octane, 1-ethoxy- Ethyl octyl etherC₁₀ H₂₂ O 186.7 ± 3.0 0.791 ± 0.06 Octane, 1-propoxy- Propyl octyl etherC₁₁ H₂₄ O 204.0 ± 3.0 −46.0 0.7883 Octane, 1-butoxy- Butyl octyl etherC₁₂ H₂₆ O 222.9 ± 8.0 −44.0 0.7925 Octane, 1-(2- Isobutyl octyl etherC₁₂ H₂₆ O 217.0 ± 3.0 −43.0 0.7856 methylpropoxy)- Octane, 1-(1-(1-Methylpropyl) C₁₂ H₂₆ O 215-217 −54.0 0.7891 methylpropoxy)- octylether Octane, 1- Pentyl octyl ether C₁₃ H₂₈ O 240.9 ± 8.0 0.803 ± 0.06(pentyloxy)- Octane, 1-(3- Isopentyl octyl C₁₃ H₂₈ O  235 ± 3.0 −56.50.7938 methylbutoxy)- ether Nonane, 1-butoxy- Butyl nonyl ether C₁₃ H₂₈O 240.9 ± 8.0 0.803 ± 0.06 Decane, 1-methoxy- Methyl decyl ether C₁₁ H₂₄O 215.2 ± 3.0 0.795 ± 0.06 Decane, 1-ethoxy- Ethyl decyl ether C₁₂ H₂₆ O225.1 ± 3.0 0.799 ± 0.06 Decane, 1-propoxy- Propyl decyl ether, C₁₃ H₂₈O 243.9 ± 3.0 0.803 ± 0.06 Decane, 1-butoxy- Butyl decyl ether C₁₄ H₃₀ O258.3 ± 8.0 0.806 ± 0.06 Dodecane, 1- Propyl dodecyl C₁₅ H₃₂ O 276.3 ±3.0 0.808 ± 0.06 propoxy- ether Dodecane, 1-butoxy- Butyl dodecyl C₁₆H₃₄ O 291.4 ± 8.0 0.810 ± 0.06 ether Jet Fuel A1 C₈-C₁₆ NA - <−470.775-0.840 (specification) mixture g/cm3 Jet Fuel A C₈-C₁₆ NA - <−400.775-0.840 (specification) mixture Bio-Diesel (example) C₁₆-C₂₂ NA - ~00.870-0.890 mixture

As can be readily seen from table 1, the variation in boiling pointfollows the number of carbon atoms whereas, surprisingly, the meltingpoint does not, allowing for synthesis of low-melting ethers with highboiling point. From the physical data presented it can be seen that thefamily of compounds disclosed can be varied to allow for specificcombinations of melting point and vapour pressure (boiling point). Theinvention relates to these variations in physical properties, byvariation of the number of carbon atoms, and the degree of branching inthe aliphatic chains utilized. Indeed the necessary physical propertiesmay be obtained by following the routes disclosed in the following,pertaining specifically to the pure ethers—composite properties can beobtained by blending of aliphatic ethers with different structures, orby admixing of aliphatic ethers or the mixture thereof with jet fuel, orby admixture of aliphatic ethers or mixtures thereof with hydrocarbonfuel not specified to jet aviation regulations, but where the fuelmixture obtained does conform to jet aviation fuel specification.

The overall boiling point of the fuel can be optimized for a specificapplication by controlling the overall number of carbon atoms in thealiphatic ether. Thus one can, as an example but not limited to; Butylpropyl ether with seven carbon atoms BP 118° C., Ethyl pentyl ether with7 carbon atoms BP 119-120° C., Ethyl hexyl ether with eight carbon atomsBP 136-137° C., Isopropyl pentyl ether with eight carbon atoms BP(calc.) 130±3, Methyl octyl ether with nine carbon atoms BP 170-172° C.,Dipentyl ether with ten carbon atoms BP 188° C., Methyl n-decyl etherwith eleven carbon atoms BP 189° C., 1-Methyl-propyl)-octyl ether withtwelve carbon atoms BP 215-217° C., Iso-pentyl octyl ether with thirteencarbon atoms BP 235° C.

The melting point of the aliphatic ethers, and thus the low-temperatureproperties can be modified by selecting the chain-length and branchingof the aliphatic chains. Examples according to the invention being, butnot limited to; Dipentyl ether with ten carbon atoms MP −69° C.,Iso-pentyl octyl ether with thirteen carbon atoms MP −56.5° C.,1-Methyl-propyl)-octyl ether with twelve carbon atoms MP −54° C., Methyloctyl ether with nine carbon atoms MP −52.5° C. As can be seen themelting point surprisingly does not follow the number of carbon atoms,and indeed in the examples given Methyl octyl ether with nine carbonatoms exhibit a melting point of −52.5° C., while Iso-pentyl octyl etherwith thirteen carbon atoms exhibit a melting point of −56.5° C. One canthus directly control the melting point by preparing ethers where theshortest chain of the aliphatic ether has one, two, three, four, five,or six carbon atoms, and where the chain can be either un-branched as ine.g. Dipentyl ether or branched as in Iso-pentyl octyl ether. The longerchain of the ether can, following the same rules, have four, five, six,seven, eight, nine, eleven, twelve, thirteen or fourteen carbon atoms,and said chain can be either un-branched as in e.g. Dipentyl ether orbranched as in Iso-pentyl octyl ether. Furthermore the aliphatic etherscan be symmetrical such as Dipentyl ether or unsymmetrical such asMethyl octyl ether.

The aliphatic ethers may be used as an jet aviation fuel in the pureform as single compounds, or they may be used as a mixture of differentethers of the type disclosed. The aliphatic ether or mixtures ofaliphatic ethers may be used as an jet aviation fuel (100%) or they maybe used in mixtures such as, but not limited to, 50%, 25%, 10% or until5% of the aliphatic ether or mixtures of aliphatic ethers, admixed withconventional jet aviation fuel.

The aliphatic ether or mixtures of aliphatic ethers may be used as a jetaviation fuel in mixtures such as, but not limited to, 50%, 25%, 10% oruntil 5% of the aliphatic ether or mixtures of aliphatic ethers, admixedwith conventional hydrocarbon fuel where the fuel obtained conforms tojet aviation fuel standards even when the conventional hydrocarbon fueladmixed does not.

Accordingly, in one aspect the present invention relates to a jetaviation fuel comprising one or more aliphatic ether compounds havingthe general formula (I):

R1-O—R2

wherein R1 and R2 individually are selected from aliphatic carbonchains.

In one embodiment of the present invention the jet aviation fuel of thepresent invention, the total number of carbon atoms of the aliphaticether compound is at least 6.

In another embodiment of the present invention the total number ofcarbon atoms of the aliphatic ether compound is at least 7.

In another embodiment of the present invention the total number ofcarbon atoms of the aliphatic ether compound is at least 8.

In another embodiment of the present invention the total number ofcarbon atoms of the aliphatic ether compound is at least 9.

In another embodiment of the present invention the total number ofcarbon atoms of the aliphatic ether compound is at least 10.

In another embodiment of the present invention the total number ofcarbon atoms of the aliphatic ether compound is at least 11.

In another embodiment of the present invention the total number ofcarbon atoms of the aliphatic ether compound is at least 13.

In one embodiment of the present invention the aliphatic carbon chain offormula I comprising the lowest number of carbon atoms comprises atleast one carbon atom. In one embodiment the aliphatic carbon chaincomprising the lowest number of carbon atoms is R1. In anotherembodiment the aliphatic carbon chain comprising the lowest number ofcarbon atoms is R2.

In one embodiment of the present invention the carbon chain of formula(I) comprising the lowest number of carbon atoms comprises at least twocarbon atoms.

In one embodiment of the present invention the carbon chain of formula(I) comprising the lowest number of carbon atoms comprises at leastthree carbon atoms.

In one embodiment of the present invention R1 and R2 of formula (I)comprises the same number of carbon atoms.

In one embodiment of the present invention R1 and R2 are bothun-branched.

In another embodiment of the present invention R1 is branched while R2is un-branched.

In another embodiment of the present invention R2 is branched while R1is un-branched.

In one embodiment of the present invention the one or more aliphaticether compounds are two, three, four, five, six, seven, eight, nine,ten, eleven, twelve or more different aliphatic ether compounds, whereinthe two, three, four, five, six, seven, eight, nine, ten, eleven, twelveor more different aliphatic ether compounds individually are as definedherein above.

In one embodiment of the present invention the one or more aliphaticether compounds are 13 or more different aliphatic ether compounds, suchas 14 or more different aliphatic ether compounds, for example 15 ormore different aliphatic ether compounds, such as 16 or more differentaliphatic ether compounds, for example 17 or more different aliphaticether compounds, such as 18 or more different aliphatic ether compounds,for example 19 or more different aliphatic ether compounds, such as atleast 20 or more different aliphatic ether compounds, and wherein saiddifferent aliphatic ether compounds individually are as defined hereinabove.

In one embodiment of the present invention the one or more aliphaticether compound is selected from the group consisting of Propyl butylether, Diisopentyl ether, Propyl pentyl ether, Isopropyl pentyl ether,Butyl pentyl ether, Pentyl ether, Methyl hexyl ether, Ethyl hexyl ether,Propyl hexyl ether, Isopropyl hexyl ether, Butyl hexyl ether,(1-Methylpropyl) hexyl ether, Pentyl hexyl ether, Hexyl ether, Methylheptyl ether, Ethyl heptyl ether, Propyl heptyl ether, Butyl heptylether, Pentyl heptyl ether, Isoamyl heptyl ether, Methyl octyl ether,Ethyl octyl ether, Propyl octyl ether, Butyl octyl ether, Isobutyl octylether, (1-Methylpropyl) octyl ether, Pentyl octyl ether, Isopentyl octylether, Butyl nonyl ether, Methyl decyl ether, Ethyl decyl ether, Propyldecyl ether, Butyl decyl ether, Propyl dodecyl ether and Butyl dodecylether.

In one embodiment of the present invention the one or more aliphaticether compound is selected from the group consisting of aliphatic ethercompounds having a boiling point between 115° C. and 300° C., preferablybetween 200° C. and 300° C.

In one embodiment of the present invention the one or more aliphaticether compound is selected from the group consisting of aliphatic ethercompounds having a density of between 0.71 and 0.82 g/cm³.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains a 50% admixture of conventional jetaviation fuel.

In another embodiment the present invention the jet aviation fuelconsists entirely of one or more aliphatic ether compounds wherein saiddifferent aliphatic ether compounds are as defined herein above.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains at least a 55% admixture of conventionaljet aviation fuel, such as at least a 60% admixture of conventional jetaviation fuel, for example at least a 65% admixture of conventional jetaviation fuel.

In one embodiment the jet aviation fuel of the present inventioncontains a 75% admixture of conventional jet aviation fuel, such as atleast a 80% admixture of conventional jet aviation fuel, for example atleast a 85% admixture of conventional jet aviation fuel, such as atleast a 87% admixture of conventional jet aviation fuel,

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains a 90% admixture of conventional jetaviation fuel, such as at least a 91% admixture of conventional jetaviation fuel, for example at least a 92% admixture of conventional jetaviation fuel, such as at least a 93% admixture of conventional jetaviation fuel, for example at least a 94% admixture of conventional jetaviation fuel, such as at least a 95% admixture of conventional jetaviation fuel, for example at least a 96% admixture of conventional jetaviation fuel, such as at least a 97% admixture of conventional jetaviation fuel, for example at least a 98% admixture of conventional jetaviation fuel, such as at least a 99% admixture of conventional jetaviation fuel.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains an at least 50% admixture of aconventional hydrocarbon fuel, and wherein the fuel mixture thusobtained conforms to jet aviation fuel standards.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains an at least 55% admixture of aconventional hydrocarbon fuel, and wherein the fuel mixture thusobtained conforms to jet aviation fuel standards.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains an at least 60% admixture of aconventional hydrocarbon fuel, and wherein the fuel mixture thusobtained conforms to jet aviation fuel standards.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains an at least 65% admixture of aconventional hydrocarbon fuel, and wherein the fuel mixture thusobtained conforms to jet aviation fuel standards.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains an at least 70% admixture of aconventional hydrocarbon fuel, and wherein the fuel mixture thusobtained conforms to jet aviation fuel standards.

In one embodiment of the present invention the jet aviation fuel asdefined herein above an at least 75% admixture of a conventionalhydrocarbon fuel, and wherein the fuel mixture thus obtained conforms tojet aviation fuel standards.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains an at least 80% admixture of aconventional hydrocarbon fuel, and wherein the fuel mixture thusobtained conforms to jet aviation fuel standards.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains an at least 85% admixture of aconventional hydrocarbon fuel, and wherein the fuel mixture thusobtained conforms to jet aviation fuel standards.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains an at least 90% admixture of aconventional hydrocarbon fuel, and wherein the fuel mixture thusobtained conforms to jet aviation fuel standards.

In one embodiment of the present invention the jet aviation fuel asdefined herein above contains an at least 95% admixture of aconventional hydrocarbon fuel, and wherein the fuel mixture thusobtained conforms to jet aviation fuel standards.

In one embodiment of the present invention the jet aviation fuel asdefined herein above is not for use for increasing the engine power ininternal combustion gasoline engines.

In one embodiment of the present invention defined herein above, R1 isnot methyl, when R2 is C5 or C6 alkyl, phenyl or benzyl.

In one embodiment of the present invention defined herein above, R2 isnot methyl, when R1 is C5 or C6 alkyl, phenyl or benzyl.

Similarly, in one aspect the present invention relates to the use of thejet aviation fuel as defined herein above in a jet engine.

In one embodiment, said jet engine is selected from the group consistingof turbojet engine, turboprop jet engine, turbofan jet engine, andturboshaft jet engine.

In one aspect the present invention relates to a container comprisingthe jet aviation fuel as defined herein above.

In another aspect the present invention relates to an aerial vehiclecomprising the container defined herein above.

In yet another aspect the present invention concerns an aerial vehiclecomprising the jet aviation fuel as defined herein above.

EXAMPLES

In the following is given examples of jet aviation fuel compositions ofthe current invention. It is to be understood that the examples in thefollowing are by no means exhaustive or limiting for the invention, andare only provided to illustrate some embodiments of the invention.

Jet aviation fuel compositions vary widely according to geographicalvariation and intended application. As an example the requirements forfuel used for long distance flying such as e.g. transatlantic crossingsposes stricter limits as to low temperature performance as compared toless demanding application. Below in Table 2 are shown pertinentparameters for some of the commonly used jet-fuel specifications:

TABLE 2 Fuel specification Jet A Jet A-1 TS-1 Jet B Initial boilingpoint ° C. — Report 150 Report 10% recovery max ° C. 205 205 165 Report50% recovery max ° C. Report Report 195 Min 125-max 190 90% recovery max° C. Report Report 230 Report End point ° C. 300 300 250 Report Freezingpoint, max ° C. −40 −47 −50 −51

It should be emphasized that the current standards are aimed atqualifying fuels from hydrocarbon stock, and that work is currently inprogress within the auspices of national bodies of standardization suchas ASTM to develop standards specifically targeting bio-fuel.(Kirk-Othmer Encyclopedia of Chemical Technology, ISBN 9780471238966,“Jet-Fuels”, p1-31 and Chevron, Aviation Fuels Technical Review (FTR-3),2006)

The examples below serving to illustrate how distillation and meltingprofile of commercial offerings can be accommodated by the fuelformulations of the invention, either as ether only fuel or admixed withfossil fuel.

Example 1

Propyl butyl ether 15% Ethyl heptyl ether 10% Butyl decyl ether 25%Methyl decyl ether 25%

Example 2

Fuel according to specification Jet B 75% Formulation example 1 25%

Example 3

Fuel according to specification Jet B 25% Formulation example 1 75%

Example 4

Methyl heptyl ether 10% Methyl octyl ether 40% (1-Methylpropyl) octylether 40% Isopentyl octyl ether 10%

Example 5

Fuel according to specification TS-1 75% Formulation example 4 25%

Example 6

Fuel according to specification TS-1 25% Formulation example 4 75%

Example 7

Propyl hexyl ether 10% Hexyl ether 90%

Example 8

Fuel according to specification Jet A-1 25% Formulation example 7 75%

Example 9

Fuel according to specification Jet A-1 25% Formulation example 7 75%

Example 10

Propyl hexyl ether 10% Hexyl ether 40% Ethyl decyl ether 50%

Example 11

Fuel according to specification Jet A 25% Formulation example 10 75%

Example 12

Fuel according to specification Jet A 25% Formulation example 10 15%

Thus in summary a jet aviation fuel based on aliphatic ethers isdisclosed where the fuel consist of one or more compounds according tothe invention, a mixture of compounds according to the invention, amixture of the pure or mixed aliphatic ethers admixed with conventionaljet aviation fuel, or a mixture of said ethers with conventionalhydrocarbon fuel, giving a product conforming to a jet aviation fuelstandard.

The foregoing description of the specific embodiments will so fullyreveal the general nature of the present invention that others skilledin the art can, by applying current knowledge, readily modify or adaptfor various applications such specific embodiments without undueexperimentation and without departing from the generic concept, andtherefore, such adaptations and modifications should and are intended tobe comprehended within the meaning and range of equivalents of thedisclosed embodiments. It is to be understood that the phraseology orterminology employed herein is for the purpose of description and not oflimitation. The means, materials, and steps for carrying out variousdisclosed functions may take a variety of forms without departing fromthe invention.

1-55. (canceled)
 56. A jet aviation fuel comprising an aliphatic ethercompound of formula (I):R1-O—R2 wherein R1 and R2 individually are aliphatic carbon chains. 57.The jet aviation fuel of claim 56, the aliphatic ether compound offormula (I) having a total number of carbon atoms in the range of 6 to16.
 58. The jet aviation fuel of claim 56, R1 having 1 to 10 carbonatoms.
 59. The jet aviation fuel of claim 58, R1 having 1 to 3 carbonatoms and R2 having 4 to 10 carbon atoms.
 60. The jet aviation fuel ofclaim 56, R2 having 1 to 10 carbon atoms.
 61. The jet aviation fuel ofclaim 60, R2 having 1 to 3 carbon atoms and R1 having 4 to 10 carbonatoms.
 62. The jet aviation fuel of claims 56, R1 and R2 individuallybeing un-branched aliphatic carbon chains.
 63. The jet aviation fuel ofclaim 56, the aliphatic ether compound of formula (I) being selectedfrom the group consisting of propyl butyl ether, diisopentyl ether,propyl pentyl ether, isopropyl pentyl ether, butyl pentyl ether, pentylether, methyl hexyl ether, ethyl hexyl ether, propyl hexyl ether,isopropyl hexyl ether, butyl hexyl ether, (1-methylpropyl) hexyl ether,pentyl hexyl ether, hexyl ether, methyl heptyl ether, ethyl heptylether, propyl heptyl ether, butyl heptyl ether, pentyl heptyl ether,isoamyl heptyl ether, methyl octyl ether, ethyl octyl ether, propyloctyl ether, butyl octyl ether, isobutyl octyl ether, (1-methylpropyl)octyl ether, pentyl octyl ether, isopentyl octyl ether, butyl nonylether, methyl decyl ether, ethyl decyl ether, propyl decyl ether, butyldecyl ether, propyl dodecyl ether and butyl dodecyl ether.
 64. The jetaviation fuel of claim 56, the aliphatic ether compound of formula (I)having a boiling point between 115° C. and 300° C.
 65. The jet aviationfuel of claim 56, the aliphatic ether compound of formula (I) having adensity of between 0.71 and 0.82 g/cm³.
 66. The jet aviation fuel ofclaim 56, further comprising at least 25% of a conventional jet aviationfuel.
 67. The jet aviation fuel of claim 66, the conventional jetaviation fuel being at least 75% to 99% of the jet aviation fuel. 68.The jet aviation fuel of claim 66, the conventional jet aviation fuelbeing selected from the group consisting of Jet A, Jet A-1, TS-1, Jet Bor combinations thereof.
 69. The jet aviation fuel of claim 66, theconventional jet aviation fuel being a hydrocarbon fuel having a mixtureof components each having a total number of carbon atoms in the range of8 to
 16. 70. The jet aviation fuel of claim 66, the jet aviation fuelhaving more than one aliphatic ether compound of formula (I).
 71. Thejet aviation fuel of claim 70, the more than one aliphatic ethercompound of formula (I) being selected from the group consisting ofpropyl butyl ether, diisopentyl ether, propyl pentyl ether, isopropylpentyl ether, butyl pentyl ether, pentyl ether, methyl hexyl ether,ethyl hexyl ether, propyl hexyl ether, isopropyl hexyl ether, butylhexyl ether, (1-methylpropyl) hexyl ether, pentyl hexyl ether, hexylether, methyl heptyl ether, ethyl heptyl ether, propyl heptyl ether,butyl heptyl ether, pentyl heptyl ether, isoamyl heptyl ether, methyloctyl ether, ethyl octyl ether, propyl octyl ether, butyl octyl ether,isobutyl octyl ether, (1-methylpropyl) octyl ether, pentyl octyl ether,isopentyl octyl ether, butyl nonyl ether, methyl decyl ether, ethyldecyl ether, propyl decyl ether, butyl decyl ether, propyl dodecyl etherand butyl dodecyl ether.
 72. The jet aviation fuel of claim 56, the jetaviation fuel being not for use in internal combustion gasoline engines.73. The jet aviation fuel of claim 56, the jet aviation fuel being foruse in a jet engine.
 74. A jet aviation fuel comprising: i. at least 25%of a hydrocarbon jet fuel admixture, wherein the hydrocarbon jet fueladmixture being not for use in an internal combustion gasoline engine,and ii. at least 25% of two or more aliphatic ether compounds.
 75. Thejet aviation fuel of claim 74, the two or more aliphatic ether compoundsbeing selected from the group consisting of propyl butyl ether,diisopentyl ether, propyl pentyl ether, isopropyl pentyl ether, butylpentyl ether, pentyl ether, methyl hexyl ether, ethyl hexyl ether,propyl hexyl ether, isopropyl hexyl ether, butyl hexyl ether,(1-methylpropyl) hexyl ether, pentyl hexyl ether, hexyl ether, methylheptyl ether, ethyl heptyl ether, propyl heptyl ether, butyl heptylether, pentyl heptyl ether, isoamyl heptyl ether, methyl octyl ether,ethyl octyl ether, propyl octyl ether, butyl octyl ether, isobutyl octylether, (1-methylpropyl) octyl ether, pentyl octyl ether, isopentyl octylether, butyl nonyl ether, methyl decyl ether, ethyl decyl ether, propyldecyl ether, butyl decyl ether, propyl dodecyl ether and butyl dodecylether.